Multiplexing arrangement for electronic organs

ABSTRACT

A single diode keying arrangement is connected for use with a plurality of keyboards, pedals, stop knobs and other switch operating instrumentalities on a time sharing basis by means of a sequential pulsing arrangement.

v United States Patent Inventor Paul A. Klann P.O.Box 2398, Waynesboro,Va. 22981 Appl. No. 859,217

Filed Aug. 15, 1969 Patented Oct. 19, 1971 Continuation-impart ofapplication Ser. No. 753,978, Aug. 20, 1968.

MULTIPLEXING ARRANGEMENT FOR ELECTRONIC ORGANS 7 Claims, 6 Drawing Figs.

U.S. Cl 84/l.0l, 84/l.03, 84/1.08, 84/1.14

Int. Cl Gl0h l/00 Field of Search... 84/1.01,

10 KC. SHIFT OSC, REC.

[56] References Cited UNITED STATES PATENTS 3,255,292 6/1966 Park 84/119 X 3,297,812 1/1967 Cordry 84/1.0l 3,358,068 12/1967 Campbell, Jr.84/1 .01 3,389,211 6/1968 Slaats 84/1.0l 3,482,027 12/ 1969 Okamoto etal. 84/1 .03 3,518,352 6/1970 Plunkett 84/1.03

Primary Examiner-Herman Karl Saalbach Assistant Examiner-SaxfieldChatmon, Jr. Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT:A single diode keying arrangement is connected for use with a pluralityof keyboards, pedals, stop knobs and" other switch operatinginstrumentalities on a time sharing basis by means of a sequentialpulsing arrangement.

swau MANUAL BUS 42 GREAY MANUAL BUS PATENTEUUU 1 ml 3.614.287

' SHEET 2 0F 3 v TIME INVENTOR PAUL A. KLANN ATTORNE YS Pmmmum 19m3.614.287 v SHEET 36F a INVENTOR I PAUL A. KLANN BY ATTORNEYSMULTIPLEXING ARRANGEMENT FOR ELECTRONIC ORGANS CROSS-REFERENCE TORELATED APPLICATION The present application is a continuation-in-part ofU.S. application Ser. No. 753,978 filed Aug. 20,1968.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention is broadly related to the field of organs and moreparticularly to an electronic switching assembly useful as a key actionfor organs.

2. Description of the Prior Art In electric organs, and also in pipeorgans, each of the keys on the various keyboards, pedals, stop knobsand other instrumentalities, are utilized to control a plurality ofintermediate electrical switches which in turn control the ultimatesoundproducing mechanisms. These key or pedal and stop operated switchesare often formed in a matrix arrangement so that one key and one stopmay provide a plurality of different combinations of switching and arecommonly called key actions or couplers. Key actions can be coupleddirectly to manual keyboards or pedal keyboards and in addition this keyaction can also be remotely controlled by mechanical actuators commonlyknown and used in the art.

In the key action switches for use in organs, it is common andconventional practice to utilize relatively light contact pressure forclosing the contacts of the actuated switch or switches. After severaldays of inactivity, quite often an insulating oxide film will form onthe switch contact which will not be broken when the organ is again usedand the key is pressed to actuate the switches. Hence, the insulatingfilm will prevent the switch contacts from mating and no sounds will beproduced by the organ unless this insulating oxide film is broken andconductive contacts can be made.

Key actions or couplers are sometimes rendered inoperative by thecollection of dirt and dust which will accumulate on theaction,particularly if the switches are exposed. Also, in prior artorgans, the key actions needed adjustments periodically due to themanufacturing process.

A major drawback of the prior art organs resided in the fact that aseparate key action was needed for each keyboard or pedal boardarrangement thereby greatly increasing the manufacturing cost due to theincreased number of parts and the increased assembly time required forassembling a key action. Furthermore, a great deal of space was requiredin the prior art organs to accommodate the large number of key actions.

In recent years, some of these disadvantages, such as exposed contactsand frequent adjustments, have been overcome by the use of solid-statekeyers. However, even with the use of solid-state keying, manydisadvantages still existed since ,on an average sized organ at leastfive keyers were necessary to accommodate the full complement ofcouplers. This resulted in the use of many .components which aresubjected to failure, are costly and require extreme care in assemblingdue to the multiplication of connections, solder joints, all of whichcan contribute to failure of operations. SUMMARY OF THE INVENTIONAccording to the present invention, all of the above-mention eddrawbacks existing'in the prior art key actions for electric organs arecompletely removed and a simple, compact, efficient and reliable keyaction is provided. In the present in vention, a single solid-statekeyer, which may be referred to as a diode keying arrangement, isutilized in place of the plurality of key actions which were required inprior art organs having a plurality of keyboards, pedal boards andstops. I

According tothe present invention, a pulse generator is provided whichgenerates a plurality of pulses in continuous sequence to sequentiallyconnect each keyboard or coupler to the sound producing relays foroperations thereof. Thus, when the pulse-generating device is operating,even though the organist is not playing the organ, the opportunity forcompleting a circuit from the organ console to the sound producingrelays is always present.

According to the present invention, it is possible to use the singlediode keyer for any number of couplers merely by generating a number ofpulses in sequence equal to the number of couplers so that each couplermay be connected periodically in sequence.

Thus, it is obvious that the present invention substantially reduces thespace requirements in an electrically operated organ, increases thereliability of performance due to the reduced number of electricalconnections and the use of solid state switching in lieu of exposedelectrical contacts, and substantially reduces cost due to the greatlyreduced number of parts required in a particular organ.

Other features of the invention will be pointed out in the followingdescription and claims'and illustrated in the accompanying drawings,which disclose, by way of example, the principles of the invention andthe best mode which has been contemplated of applying those principles.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a wiring diagram showing theelectrical connections between the pulse generator and the diode keyer;

FIG. 2 is a wiring diagram showing the connection of the I diode keyerwith respect to a single key operated switch, as

- single coupler switch and a single sound producing relay;

FIG. 3 is a graphical representation of the output of the pulsegenerator;

FIG. 4 is a schematic showing of a modified arrangement for holding acircuit closed;

FIG. 5 is a simplified schematic diagram of a circuit which illustratedthe principles of operation of an output circuit according to anotherembodiment of the invention; and

FIG. 6 is a detailed schematic diagram of the output circuit accordingto another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION a plurality of key operatedswitches, pedal operated switches,

stop operated switches and sound producing relays.

Tuming first to FIG. 2 which illustrates the operation of a diode keyer,a single key operated switch K1 and a single coupler switch C16 areconnected in circuit with the diode keyer to operate a sound producingcontrol relay 5. Upon closing of the key switch K1, a positive potentialappears at point 1. If coupler switch C16 is closed, this positivepotential is now at ground potential thereby not allowing anything tohappen. However, if the coupler switch C16 is open, this positivepotential appears at the base of transistor 4 thereby causing transistor4 to assume an ON" condition allowing relay coil 5 to operate. Resistor3 is to limit the current flow to the transistor 4 and diodes 6 and 7are to prevent feedback from other portions of the circuit. Diode 8 isused to suppress the electrical kickback" of coil 5. The circuit of FIG.2 thus coil 5 to maintain an ON condition by a series of pulses insteadof a steady DC power source. Itis also possible to have the capacitor inthe base circuit of the transistor 4 but this arrangement would requireadditional components which are well known by those skilled in the art.

Another possible mode for maintaining the relay 5 energized in lieu ofthe capacitor arrangement previously described is shown in FIG. 4. Autility circuit includes a reed switch 60 which is normally in the opencondition. A magnetic core 64 is slidably mounted in a hollowcylindrical nonmagnetic sleeve 62 around which the coil 70 is wrapped.The core 64 is nonnally maintained in the position shown in FIG. 4remote from the reed switch 60 by the coil spring 68 extending betweenthe sleeve 62 and the flange 66 on the core 64. If a train of discretepulses is applied to coil 70 each pulse will create a magnetic field todraw the core 64 into the sleeve into close proximity to the reed switch60 causing the switch to close. Upon the tennination of each pulse thediode 72 which is connected across the coil 70 retards the collapse ofthe magnetic filed. This retardation plus the inertia of the magnet 64results in the reed switch 60 remaining closed until a sub sequent pulseis applied to the coil 70.

The pulse generator, generally indicated at 30 in FIG. 1, may be any oneof many different generators. As illustrated in FIG. 1 the pulsegenerator is comprised of a kc./s oscillator 32 connected to a shiftregister 34 which in turn is connected to a gate amplifier 36. The gateamplifier 36 may be provided with a number of outputs equal in number tothe number of pulses being generated for the particular application.Three such outputs 37-39 are shown coupled to further circuitry.Operation of the circuit in the presence of a pulse on each of theselines is discussed below. The dashed lines are used to illustrate otheroutputs from the gate amplifier 36. A SWELL manual bus bar 40 and aGREAT manual bus bar 42 are provided for each of two keyboard manuals.Each of these bus bars is adapted to be connected to a source ofpositive potential by means of switches 12 and 13, respectively. Theswitches 12 and 13 may be transistors. Upon closure of either switch Klby depressing a key on the SWELL manual or GREAT manual or K1 the SWELLmanual bus 40 or the GREAT manual bus 42, respectively, may be connectedto the diode keyer in the dotted circle 44. The diode keyer 44 issimilar to that described above with respectto FIG. 2.

A plurality of couplers bus bars such as SWELL to GREAT, SWELL to SWELL,etc. are each provided as bus bars 46, 48 and 50, respectively.Individual coupler switches C4, C8 and C16 within a particular couplerbus, are provided to selectively connect the particular coupler bus to adiode keyer 44 and the individual coupler switches in a particularcoupler bus may be preset by means of a combination action or setindividually as desired. The individual coupler switches allow theorganist to play a specific pipe in an organ depending upon the closureof a selected key in a manual. Coupling is well known in the organ art.It is a way of squeezing more out of a given number of pipes withoutsubstantial cost. Coupler switches may be used to change the pitch of anote played on a keyboard manual. For example, let us considerintramanual coupling. Such coupling has its entire effect on one manualof the organ. When coupling switch C16 on the SWELL to SWELL bus bar 48is set all voices on the SWELL manual produce a sound an octave lowerthan would be sounded if coupling switch C8 was set. A more detaileddescription of coupling is given in Electronic Musical Instruments,Richard H. Dorf, Radiofile, 1968. The three bus bars 46, 48 and 50 areeach connectable to a negative potential by means of switches 20, 10 and11, respectively, These three switches 20, 10 and 11 are transistors.

Although a particular electric organ may have a plurality of differentorgans, only the SWELL relay 52 and the GREAT relay 54 are shown in FIG.1 for purposes of illustration. The SWELL relay 52 may be connected tothe SWELL bus 53 by means of transistor 16 which may be turned ON orOFF" by means of a signal received from the diode' keyer 44. The SWELLbus bar 53 is connectable to a negative potential by means of atransistor 14R which is turned ON" and "OFF" by means of a pulsereceived from the pulsing arrangement 30. Likewise, the GREAT relay 54is connected to the GREAT bus bar 55 by means of the transistor 41 whichis controlled by the diode keyer 44. The GREAT bus bar 55 is connectableto a source of negative potential through a transistor 15R under thecontrol of a pulse from the pulsing arrangement 30;

FIG. 3 represents the output of the pulse generator. With the passing oftime a pulse 17 is generated. Immediately on ceasing, pulse 18 isgenerated and following its completion pulse 19 is generated. This cycleis repeated continuously at a fixed rate depending on the motor speed ormaster control oscillator triggering a ring counter or shift register.The number of pulses generated is dependent upon the number of keyboardsand coupler buses in the particular organ under consideration.

The average two manual organ console lists coupler, (C) switches asfollows:

SWELL to SWELL l6 SWELL to SWELL 8 SWELL to SWELL 4' SWELL to GREAT 16'SWELL to GREAT 8' SWELL to GREAT 4 GREAT to GREAT 16' GREAT to GREAT 8'GREAT to GREAT 4' In the above listing, the prime markings are thepitches of the tone as compared to what is being played at the keyboard.As an example, with a 16' switch in operation, the tone produced will bean octave lower than what is being played. With an 8' switch inoperation, the pitch is known as Unison pitch. With a 4' switch inoperation, the tone produced is an octave higher. In addition tochanging pitches within a manual, one manual may be coupled to anothermanual at various pitches.

For an organist to produce a tone from the keyboard, a coupler switchhas to be opened by means of moving the coupler tablet to the ON"position and a K switch has to be closed by the pressing of a key. Thisin itself would not produce a tone if all the bus lines shown in FIG. 1were to remain disconnected from a power source. However, the bus linesdo not remain in the open position due to the sequential closing of aseries of bus switches controlled by the pulse generator. In theparticular example shown, the bus switches are transistors which may becontrolled by the pulses from the pulse generator. By preselected wiringof the pulses through diodes to their respective bus switch, the diodekeyer is made to operate as follows.

Pulse 17 will operate the SWELL to SWELL coupler bus and for this totake place the generation of pulse 17 on line 38 will cause transistors10, I2 and 14R to be closed. Pulse 18 on line 37 will operate the SWELLto GREAT coupler bus and for this to take place the generation of pulse18 will cause transistors 20, 13 and 14R to be closed. Pulse 19 on line39 will operate the GREAT to GREAT couplers and for this to take placethe generation of pulse 19 will cause the transistors 11, 13 and 15R tobe closed. The above sequence of pulses and operations will be repeatedindefinitely as long as the pulse generator is operating. 1

More specifically, the operation of the device as a result of thegeneration of the pulse 17 is as follows. The pulse 17 will cause thetransistor 12 to turn "ON" thereby energizing the SWELL manual bus bar40. The same pulse 17 will simultaneously turn transistor 10 ,to the ON"state thereby energizing the SWELL to SWELL coupler bus bar 48 and turnthe transistor 14R to the ON" state thereby energizing the SWELL bus bar53. Thus, on closing the,key switch Kl of the manual, apositivepotential will appear at the junction point of the two diodes in thediode keying arrangement 44 similar I to the manner described withrespect to FIG. 2. If the coupler switch C16 on the SWELL to SWELL bus48 is open and the remaining coupler switches C8 and C4 are closed as aresult of individual selection or as the result of a preset combinationaction, the positive potential will be applied to the base oftransistors 41 and 16. However, since the SWELL bus 53 is energized andthe GREAT bus 55 is deenergized as the result of pulse 17, only thetransistor 16 will be turned ON" thereby energizing the SWELL relay 52.i

Another way of phrasing the above operation is that a diode keyer, ofwhich is shown within the dotted circle 44 in FIG. 1, is not allocatedto any particular keyboard or coupler bus bar or coupler switch.Instead, it is community property and momentarily borrowed" by eachgroup of coupler switches in conjunction with each keyboard. Even thoughthe organist is not playing the organ, the opportunity for completing acircuit from the organ console is always present.

FIG. 5 illustrates in simplified form an output circuit which may besubstituted for the output circuit shown in FIG. 1. For purposes ofillustration, it will be assumed that the output circuit shown in FIG. 5is substituted for the SWELL output circuit comprising the transistors14R and 16 andthe relay 52. The relay coil 52 is connected in serieswith a resistor 62 to a source of negative potential. Resistor 62 has avalue which prevents the relay from closing but is not so great as toprevent the relay from holding ON once it has closed. If a signal isreceived from the key line from the diode keyer 44 the relay 52 will notoperate with resistor 62 in series. If, however, switch 14R is closed,the current is sufficient to operate the relay. Once the relay hasoperated, closing relay contact 60, the positive potential on thecontact will cause the relay to hold itself ON" as well as to operatethe load 64. Relay contact 60 will remain closed even after switch 14Ris opened. When switch 16 is closed, the relay 52 will unlock itself andstay unlocked until another pulse is received from the key linesimultaneously with the closing of switch 14R. The pulse that closesswitch 16 is the "OFF pulse. This pulse is generated by the pulsegenerator 30 and occurs before each pulse 16,

shown in FIG. 3.

Due to the slow operation of a relay, the relay 52 shown in FIG. 5 isnot practical in actual use. In reality, the, relay 52 may be asilicon-controlled rectifier, a unijunction transistor, two transistors,or any number of electronic devices capable of being locked by one pulseand unlocked by another pulse. FIG. 6 illustrates an electronic outputcircuit which may be used in place of the relay 52. This circuitincludes a pair of complementary transistors 70 and 72 connected to forma bistable circuit. The key line from the diode keyer 44 is connected tothe base of transistor 62 through series connected resistors 74 and 76.A pulse on the key line is prevented from turning transistor 72 ON bynormally conducting transistor 78 which is connected to the junction ofresistors 74 and 76 by a diode 80. However, when switch 14R is closed,transistor 82 is turned ON which robs base current from transistor 78.This causes transistor 78 to turn "OFF. Current now flows from the keyline to the base of transistor 72, turning it ON". This in turn causestransistor 70 to turn ON" thereby locking both transistors ON".Transistors 70 and 72 will remain locked ON even after switch 14R isopened. In order to turn transistors 70 and 72 OFF it is necessaryto'operate switch 66. Closing switch 66 turns on transistor 84.Transistor 84, when it is conducting, connects the base of transistor 72through diode 86 to a source of negative potential. This causestransistor 72 to turn OFF which in turn causes transistor 70 to turnOFF".

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings. It is, therefore, tobe understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically described.

What is claimed is:

I. In an organ comprising a plurality of keyboard manuals, couplerswitches, sound producing control means and keyers, the improvementcomprising;

a plurality of coupler switches, keys and sound producing control meanscoupled to a single keyer and pulse controlled time divisionmultiplexing means for sequentially interconnecting differentcombinations of coupler switches, keys and sound producing control meanswith said single keyer.

2. In an arrangement as set forth in claim 1 further including bus barmeans associated with each of said keyboard manuals,

co u Ier switches and sound producing control means, each of sal bus barmeans including switch means for selectively connecting each of said busbar means to a source of potential.

3. In an arrangement as set forth in claim 2 wherein said control meansis comprised of pulse generating means adapted to produce a plurality ofcontrol pulses cyclically, each of said control pulses in a cycle beingoperatively connected to a predetermined combination of switching meansto operate said switching means and energize a predetermined combinationof bus bar means.

4. In an arrangement as set forth in claim 3 wherein, each of said soundproducing control means includes holding means adapted to maintain therespective sound producing control means which are connected to aselected energized bus bar means in the energized state under thecontrol of a plurality of discrete pulses.

5. In an arrangement as set forth in claim 3 wherein said holding meansis a circuit which is capable of being locked by one pulse an unlockedby another pulse.

6. In an arrangement as set forth in claim 5 wherein said circuit is anelectronic bistable circuit.

7. In an arrangement as set forth in claim 6 wherein said electronicbistable circuit includes two complementary transistors connected tolock each other on when a first pulse is applied to the base of one ofsaid transistors.

1. In an organ comprising a plurality of keyboard manuals, couplerswitches, sound producing control means and keyers, the improvementcomprising; a plurality of coupler switches, keys and sound producingcontrol means coupled to a single keyer and pulse controlled timedivision multiplexing means for sequentially interconnecting differentcombinations of coupler switches, keys and sound producing control meanswith said single keyer.
 2. In an arrangement as set forth in claim 1further including bus bar means associated with each of said keyboardmanuals, coupler switches and sound producing control means, each ofsaid bus bar means including switch means for selectively connectingeach of said bus bar means to a source of potential.
 3. In anarrangement as set forth in claim 2 wherein said control means iscomprised of pulse generating means adapted to produce a plurality ofcontrol pulses cyclically, each of said control pulses in a cycle beingoperatively connected to a predetermined combination of switching meansto operate said switching means and energize a predetermined combinationof bus bar means.
 4. In an arrangement as set forth in claim 3 wherein,each of said sound producing control means includes holding meansadapted to maintain the respective sound producing control means whichare connected to a selected energized bus bar means in the energizedstate under the control of a plurality of discrete pulses.
 5. In anarrangement as set forth in claim 3 wherein said holding means is acircuit which is capable of being locked by one pulse an unlocked byanother pulse.
 6. In an arrangement as set forth in claim 5 wherein saidcircuit is an electronic bistable circuit.
 7. In an arrangement as setforth in claim 6 wherein said electronic bistable circuit includes twocomplementary transistors connected to lock each other on when a firstpulse is applied to the base of one of said transistors.